Ordinary removable dentures, dental plates and the like, comprise teeth mounted in a suitable plate or base. Denture stabilizers are used to fill the interstices between the dentures and the gums or tissues. Prior to placement of the denture in the oral cavity, a denture stabilizer is applied to the denture-plate surface which, for a perfect fit, should uniformly contact the gums and mucous tissues. The denture stabilizer is formulated not only for its adherent properties, but also to provide a cushion or gasket between the denture and the gums or tissues, thereby positioning the denture securely in the oral cavity.
Considerable effort has been made over the years to develop improved denture adhesive compositions. Both synthetic and natural polymers and gums have been used singly, in combination, and in combination with various adhesives and other materials in an attempt to lessen certain deficiencies. These deficiencies include inadequate holding power, oozing of the adhesive from under the dental plate during insertion and throughout the wearing period, and messiness and difficulty of removing the residual adhesive from the mouth and dentures. Additionally, food may become trapped between the denture and the oral cavity of the wearer.
Alkyl vinyl ether-maleic copolymers and salts thereof are known in the art for use in denture adhesive compositions. Such disclosures include: U.S. Pat. No. 3,003,988 to Germann et al., issued Oct. 10, 1961; U.S. Pat. No. 4,980,391 to Kumar et al., issued Dec. 25, 1990; U.S. Pat. No. 5,073,604 to Holeva et al., issued Dec. 17, 1991; U.S. Pat. No. 5,900,470, Prosise et al., issued May 4, 1999; U.S. Pat. No. 5,037,924, Tazi et al, issued Aug. 6, 1991; U.S. Pat. No. 5,082,913, Tazi et al., issued Jan. 21, 1992; and U.S. Pat. No. 5,525,652 to Clarke, issued Jun. 11, 1996. In addition strip or insert denture adhesives are also known. For example, U.S. Pat. No. 4,880,702 to Homan et al., issued Nov. 14, 1989 discloses a denture stabilizer in the form of a strip consisting of three layers. The two outside layers consist of a polymer selected from the group consisting of polyethylene oxide having an average molecular weight of about 200,000 to 10,000,000, sodium carboxymethylcellulose, polyvinyl alcohol, and mixtures thereof. The inside layer consists of microcrystalline wax and a polymer sufficient to adhere the inside layer to gums and a denture base, after contact with water, when the outside layers have been dissolved. European Patent Application 0,353,375 to Altwirth published Feb. 7, 1990, discloses an adhesive insert for dentures consisting of a adhesive permeated fibrous fleece and an adhesive consisting of a pasty mixture of alginate and/or carboxymethylcellulose, polyvinyl acetate and an alcoholic solvent. Despite the above-noted technologies as well as many others, a need still exists for denture stabilizing compositions providing improved hold.
In accordance with the present invention, it has been discovered that denture adhesive compositions comprising alkyl vinyl ether-maleic acid copolymers and/or terpolymers with isobutylene comprising strontium and zinc mixed salts together with specific levels of free acid, provide superior denture hold. The present denture adhesive compositions may also be effectively used as a wound dressing, underwater adhesive, a bioadhesive, a delivery vehicle for other actives, and/or any other application that requires adhesion to skin or tissue, including cosmetic pore cleansing strips.
An object of the present invention is to provide alkyl vinyl ether-maleic copolymers and/or terpolymers comprising strontium and zinc mixed salts, together with specific levels of free acid for adhesive compositions for firm hold, which may be used with dentures. These composition effectively hold dentures in place for a prolonged period of time.